Super-tiny ferrite rods anywhere?

No, I've just seen hollow fiber in some of the optics mags.

A bit of googling gives a bunch of hits.

Why not draw hollow fiber with the ferrite already inside?

But they do have the technology for getting ferrite epoxy into coils wound with #40. Wave some serious volume at them and see what happens.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation

I thought that was Corning, but I guess there could be more than one company doing it.

Rick

Then you visit a French restaurant and the price goes up by another 1000%.

--
Regards, Joerg 

http://www.analogconsultants.com/

But it's go-o-o-od eats! ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

Corning is another name in super-zoot ceramics, yes.

--
Tim Wescott 
Control system and signal processing consulting 
www.wescottdesign.com

These microscopic tubes are formed by heating until soft and then stretching a thin glass tube which starts off at about half hole by diameter, I think the hole to wall ratio is conserved during stretching.

--
?? 100% natural

down to or down by?

--
?? 100% natural

Am 22.12.2012 00:02, schrieb John Larkin:

On the time nuts mailing list we recently discussed the wire that delay lines in TEK 475 & friends were made from. Requirement was "Lots of L per millimeter"

And with a really slim form factor, there is as much air gap as way through ferrite, so the ferrite buys a factor of 2 at best.

regards, Gerhard

I discusesed with Valley Design

at a Optec fair in Germany. They're doing mostly optical, but your size requirements sound like them and handling ferrites might be doable by them.

--
Mikko OH2HVJ

Rather than trying to wind a cylinder could one etch a flat spiral from a 4-ish mil ferrite layer on a nonmagenetic substrate? Just a thought.

paul

Sorry typo. "Down to" was meant. Now if we can only get 0.005" that might be ok. 0.006" maybe not so.

--
Regards, Joerg 

http://www.analogconsultants.com/

Germany.

Aha, and they are even here in California! Thanks, Mikko. I'll put this under the Christmas tree, will call them.

--
Regards, Joerg 

http://www.analogconsultants.com/

Maybe I don't quite understand what you mean. Ferrite is non-conductive, but we need the inductor to be at least somewhat conductive. If it has a few ten ohms that would be fine though.

--
Regards, Joerg 

http://www.analogconsultants.com/

A factor of two is HUGE for us. We would open a bottle of Trappiste that night to celebrate.

--
Regards, Joerg 

http://www.analogconsultants.com/

Yes, I got that wrong. Better idea - etch a conductive spiral on top of a ferrite substrate?

I don't think anyone's suggested this idea yet, so how about rolling out th e ferrite cores between two flat plates - glass sheets perhaps? You'd have to absorb or mix ferrite dust into some sort of gummy medium that would be readily roll-able, but if that could be achieved then a pretty much uniform 5 thou diameter rod should be easily achievable, I'd have thought. Just ke ep rolling out and re-rolling until the desired diameter is obtained.

Yup, I talked about that with another engineer at a guide dog meeting yesterday. But the winding is not so much the challenge. We could get

52AWG wire, stuff one probably couldn't even see. The challenge is how to arrive at a ferrite core of this size.

--
Regards, Joerg 

http://www.analogconsultants.com/

That's almost how centerless grinding works. Except now it would be centerless rolling :-)

--
Regards, Joerg 

http://www.analogconsultants.com/

I sure wish you would/could tell us what you're actually trying to do.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators